Abstract Glass–SnO 2 samples, which are typical superstrates for thin-film solar cells, have been dipped in an appropriate sol–gel solution, and thus improved SiO 2–glass–SnO 2–SiO 2 superstrates have been obtained with a higher transmission and a smoother surface, owing to the antireflective and levelling properties of these SiO 2 films. The electrodeposition of the photovoltaic absorber CuInSe 2 has been found homogeneous on SnO 2 and heterogeneous on SiO 2-coated SnO 2. CuInSe 2 grows only onto specific SiO 2 points, and the residual substrate area remains CuInSe 2 free. Optical characterization of the samples has been performed in the visible and near-infrared spectral range. Morphological analysis have been carried out using atomic force microscopy.